The present invention relates generally to rocket motors, and, in particular, relates to an absorber for use in outer space that heats a liquid by solar energy and outputs the heated fluid to a thruster.
Satellites parked in a stationary orbit need thrusters to correct and maintain a position in orbit; otherwise, eventually, the satellite will drift out of the desired position and thus become useless. Once the satellite is correctly positioned, thrusters having a small specific impulse can be turned on and off to maintain the proper stationary orbit. Although this use of thrusters is clear, other uses are also needed where a low specific impulse is sufficient.
One thruster uses a liquid propellant and an oxidizer that are combined in the thrust chamber. Ignition occurs upon contact. This thruster requires storage of two liquids, piping for both and pumps.
Another thruster uses a liquid propellant that is heated to a high degree by an internal source. This type of thruster is heavier and requires constant standby energy to maintain the heat source in a ready state.
Another type of thruster uses an external source of heat, i.e., the sun, to heat the liquid propellant to a high degree for expansion. Previous designs of absorbers, the device to super heat the liquid propellant, were complicated, difficult to manufacture, and inefficient.
The above problems have motivated a search for a solar absorber for minimizing weight, manufacturing problems, and other inefficiencies.